Those Who Came Before is a mod where instead of players making brand new items, players scavenge abandoned machinery and wreckages around the map, then fix the machinery they gathered to make new machinery used to get the the new virtual reality dimension. One of the materials you can make from wrecks is steel.
When you make a world, you are not the only player who has joined that world. Many players have joined that world before and built structures around it. Now that those players don't exist anymore for whatever reason, all they have left behind are their old structures and abandoned machinery. Your job is to fix what they made, then use it to get to the Virtual Reality dimension...
If you ever reach the point of going to this dimension, be sure to be kitted up properly as there are a LOT of mobs there. The portal is made out of Supercomputers and lit with a mystical key. Once there, you will see a dimension with a green floor and green atmosphere. it is relitavely foggy so it is perfect for mobs to spawn. Why not try to build a base there and use an earth portal for collecting resources? As it is alpha, suggestions are welcomed.